Excerpt: “While the genome of an organism contains all its genes, it is the epigenome that decides which are expressed, or “turned on.”
Article link: Comparative Epigenomic Annotation of Regulatory DNA
In a recent review article: Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors I detailed how the epigenetic effects of nutrient chemicals from the ecological niche cause social niche construction via the metabolism of the nutrients to pheromones, which control reproduction and diversity in species from microbes to man. In mammals, the ecological niche and social niche contribute equally to construction of the neurogenic niche responsible for our cognitive niche.
It should surprise no one that nutrient chemicals and pheromones are responsible for the development of the mammalian brain that enabled construction of our cognitive niche. For example, I used the honeybee model organism to detail how what the queen eats determines the production of her pheromones that are responsible for everything that influences the behavior of the colony, including the neuroanatomy of the worker bees’ brain.
What surprises me is that anyone would dispute the significance of modeling behavioral development across the ecological, social, neurogenic, and cognitive niche construction domains by incorporating the epigenetic effects of nutrient chemicals and pheromones on intracellular signaling and stochastic gene expression. Not only do these epigenetic effects directly connect the sensory environment to the development of behavior, but they do so via the conservation of gonadotropin releasing hormone and diversification of its receptor-mediated events. The obvious conclusion is “olfaction and odor receptors provide a clear evolutionary trail that can be followed from unicellular organisms to insects to humans.”
Does anyone think a different conclusion is likely to result from the comparative epigenomic annotation of regulatory DNA or of non-coding ‘junk’ DNA? In my model the ‘junk’ must be there to allow production of the de novo olfactory receptors required for adaptive evolution. If I’m wrong, is there another model for that? If nutrient chemicals and pheromones do not cause the changes in intracellular signaling that cause the stochastic gene expression required for individual survival and the reproduction of species, what sensory cause does result in direct effects on gene expression and adaptive evolution in species from microbes to man?
We can only hope that as works like the one linked above proceed, that similarities and differences in species are considered. My preference is for more consideration of the similarities across species from microbes to man that are apparent in their common molecular biology.